JP5759815B2 - electronic microscope - Google Patents

Description

  The present invention relates to an electron microscope, and more particularly to an electron microscope equipped with a system capable of safely applying a high voltage to a sample.

  An electron microscope focuses a primary electron beam emitted from an electron gun onto a sample by a magnetic lens, detects secondary charged particles from the sample, and obtains an enlarged image of the sample. The scanning electron microscope has a function of scanning a primary electron beam on the sample by a magnetic field type or electric field type deflector installed above the objective lens.

  In general, in a scanning electron microscope, a sample is observed with a ground potential, but a sample image may be observed by applying a voltage to the sample. Particularly recently, the retarding method has become common. This is a method of observing a sample image by applying a negative voltage (retarding voltage) of about several hundred to several kV to the sample and decelerating the primary electron beam immediately before the sample.

  In the retarding method, the voltage at which the primary electron beam is accelerated by the electron gun (acceleration voltage) is Vacc, and the voltage applied to the sample (retarding voltage) is Vr. The voltage (irradiation voltage, also referred to as landing energy) Vi is represented by Vi = Vacc−Vr. When the retarding method is used, a high-quality image can be obtained even when the irradiation voltage is the same as when not used (when the sample is at ground potential). For example, when Vacc = 1 kV and Vr = 0.5 kV, and Vacc = 0.5 kV and Vr = 0 V, the irradiation voltage Vi is the same 0.5 kV, but the former has a resolution (sample image is smaller). The degree of clearness) can be improved. In addition, by using the retarding means, it is possible to observe the sample image at an irradiation voltage (for example, Vi = 0.1 kV) lower than the minimum acceleration voltage (for example, Vacc = 0.5 kV) that can be realized by the electron gun. . As a result, it is possible to realize morphological observation of the outermost surface of the sample with high resolution. In addition, observation by the retarding method has various effects such as suppression of sample charging and reduction of sample damage.

  Scanning electron microscopes can be classified into three types, an out-lens type, a semi-in-lens type, and an in-lens type, depending on the arrangement relationship between the objective lens and the sample. In the out-lens type scanning electron microscope, the sample is disposed at a position completely separated from the lens magnetic field of the objective lens. In the in-lens type, the sample is disposed in the lens magnetic field of the objective lens. The semi-in lens type is an intermediate between the out-lens type and the in-lens type, and the sample is arranged at a position where a part of the lens magnetic field of the objective lens leaks. As described above, among the three types of scanning electron microscopes, an in-lens scanning electron microscope that can utilize the lens power of the objective lens most efficiently is advantageous in that a high-resolution image can be acquired.

  In a scanning electron microscope (hereinafter referred to as an in-lens SEM) using an in-lens type objective lens, it is necessary to dispose the sample between lens magnetic poles because of the requirement that the sample be disposed in the lens magnetic field. Therefore, the sample is loaded on the tip of a dedicated sample holder, inserted into the objective lens, and an enlarged image is observed.

  However, the retarding method is an observation method in which a voltage of the same level (same order) as the acceleration voltage of the primary electron beam is applied to the sample, and the sample loaded at the tip of a dedicated sample holder is inserted between the magnetic poles of the objective lens. The retarding method has not been conventionally used in the in-lens SEM due to discharge and safety problems.

  On the other hand, although not as high as the retarding voltage, a technique for applying a voltage to the sample holder for another purpose has conventionally existed mainly in the field of transmission electron microscopes or scanning transmission electron microscopes. For example, Patent Document 1 discloses an invention in which a memory is mounted on a sample holder for the purpose of discriminating a plurality of samples mounted on the sample holder, and an external power source serving as a driving power source for the memory and the sample holder are connected by a cable. Has been.

  As a measure for ensuring safety at this time, in Patent Document 1, a cable connection sensor for determining whether or not a cable is connected to a connector for introducing a high voltage is provided. Thereby, when the cable connection sensor does not detect the cable connection state, or when the main body of the electron microscope cannot recognize the memory on the sample holder, voltage application to the sample holder is prohibited.

Japanese Patent Laying-Open No. 2005-327710 (US Pat. No. 7,381,968)

  When the retarding method is adopted for the in-lens type SEM, the retarding voltage must be applied by connecting a high voltage cable to the sample holder in view of inserting the sample holder into the objective lens. In general, the power source of the scanning electron microscope is usually stored in the gantry or provided as a power source unit different from the main body. Therefore, in the in-lens SEM employing the retarding method, a long high-voltage cable must be routed and connected from the inside of the gantry or another unit to the sample holder.

  On the other hand, in the in-lens type SEM, since the sample holder can be pulled out from the scanning electron microscope body even during observation, when such a long power cable is connected to the sample holder, the high voltage cable is connected to the operator of the apparatus. As a result, the sample holder may be accidentally pulled out of the scanning electron microscope body during operation.

  If the sample holder is pulled out in a state where a high voltage is applied, there is a risk of an electric shock from the operator, or a discharge may occur inside the electron optical column and the apparatus may be damaged.

  In Patent Document 1, the state of connection between the sample holder (connector) and the cable before the start of voltage application is a problem, and the safety during operation of the apparatus is not particularly a problem. However, when the retarding method is performed with the in-lens SEM, a much larger voltage than before is applied to the sample holder. Therefore, it is necessary to carefully examine the safety of the operator as compared with the conventional case. .

  The present invention provides a scanning electron microscope that is safer than the conventional one even when the apparatus is in operation when a retarding method is adopted for a scanning electron microscope that performs observation by inserting a sample holder into an electron optical column. An object of the present invention is to provide an electron microscope capable of performing the above operations.

  In order to solve the above-described problems, the present invention provides a sample holder having a function of applying a voltage to a sample stage on which a sample is loaded, a voltage source for supplying a voltage to be applied to the sample stage, A voltage cable connected to the sample holder, and a repeater to which the other end of the voltage cable is connected is installed in a frame or a cover that supports the lens barrel of the electron microscope.

  In this case, the length of the voltage cable is preferably shorter than the length of the sample holder. Therefore, if the repeater is arranged in a circle whose radius is smaller than the length of the sample holder from the end of the gantry or cover in a state where the sample holder is inserted into the electron optical column, the voltage cable The length can be shorter than the length of the sample holder.

  Since the repeater is installed in the gantry or cover, it is not necessary to route the high-voltage cable from the power source, so that the risk of accidentally pulling out the sample holder during operation of the apparatus is reduced.

  In addition, by setting the length of the voltage cable to be shorter than the length of the sample holder, it is possible to prevent the sample holder from being inserted into the electron optical column while the retarding voltage is applied.

  As described above, according to the present invention, in the case where the retarding method is adopted for the scanning electron microscope in which the sample holder is inserted into the electron optical column for observation, there is less risk of electric shock than before. Can provide.

1 is an overall external view of an electron microscope of Example 1. FIG. FIG. 3 is an explanatory view showing a sample holder and a sample stage of Example 1. It is a top view which shows arrangement | positioning of the repeater in the state which inserted the sample holder of Example 1. FIG. It is explanatory drawing which showed the detailed example of the periphery of the repeater of Example 1. FIG. It is explanatory drawing which showed the other detailed example of the periphery of the repeater of Example 1. FIG. It is the perspective view which showed the wiring structure inside the repeater concerning the detailed example shown to FIG. 3B. 3 is an overall external view of an electron microscope according to Example 2. FIG. It is explanatory drawing shown about arrangement | positioning of the repeater of Example 2. FIG. 6 is an overall external view of an electron microscope according to Example 3. FIG. 6 is a diagram illustrating a positional relationship between a sample holder and an objective lens in the electron microscope of Example 3. FIG.

Example 1
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In this example, a configuration example of an electron microscope including a side entry type sample holder will be described.

  FIG. 1 is a schematic diagram of an embodiment of the present invention, which is an electron microscope capable of loading a sample on a sample stage at the tip of the sample holder and applying a voltage to the sample stage via the sample holder.

  An electron optical column 1 that irradiates a sample with a primary electron beam, detects secondary charged particles obtained by the primary electron beam irradiation, and outputs it as an image signal is supported on the upper surface of a gantry 2. Furthermore, a sample stage 3 for moving the sample position is mounted on the electron optical column 1, and a sample holder 4 for applying a high voltage on which the sample is mounted is inserted.

  On the other hand, a high voltage source 7 for supplying a voltage to be applied to the sample is arranged inside the gantry 2 so that it cannot be directly touched by an operator.

  The voltage generated from the high voltage source 7 is introduced to the repeater 6 installed on the gantry 2 via the voltage cable 8 extending from the high voltage source 7, and from there to the sample holder 4 via the voltage cable 5. Once introduced, a voltage is applied to the sample on the sample stage. The repeater 6 is provided with a connection terminal to the voltage cable 5 and is used by connecting the cable to the repeater 6 when observing retarding.

  A state in which the sample holder 4 is inserted into the sample stage 3 is shown in FIG. 2A. The sample holder 4 is mounted on a side entry type sample stage 3 that is inserted from the side surface of the electron optical column 1 into the column through a vacuum feedthrough. The sample holder 4 includes a grip 11, an O-ring 12 for insertion into the high-vacuum electron optical barrel 1, a guide pin 14 for guiding the insertion direction of the sample holder 4, and a sample 13. And a shaft 16 for insulating the sample table 15 from the sample holder 4 and the electron optical column 1.

  Further, the voltage cable 5 extends from the grip 11, and a BNC connector A (male side terminal) 17 for connecting to the repeater 6 is provided at an end thereof. The high voltage applied from the BNC connector A 17 is supplied to the sample stage 15 through the voltage cable 5 by the voltage introduction line 18 inside the holder including the grip, thereby retarding the primary electron beam 19. Acts as a voltage. Here, as shown in FIG. 2A, the length L from the grip end surface of the sample holder 4 to the end surface of the sample table 15 and the length l of the voltage cable 5 have a relationship of L> l.

  As described above, when the length L of the main body of the sample holder and the length l of the voltage cable 5 satisfy the relationship of L> l, when the sample holder 4 is mounted on the sample stage 3, the sample holder is first attached. After mounting 4, it is necessary to connect the voltage cable 5 to the repeater 6. This is because the length of the voltage cable 5 is shorter than the length of the sample holder main body, and therefore the sample holder 4 cannot be attached to the sample stage 3 if the voltage cable 5 is connected to the repeater 6 first. .

  In order for L and l to satisfy the relationship L> l, it is necessary to devise the arrangement of the repeater 6 on the gantry 2. FIG. 2B shows a top view of the electron microscope with the sample holder 4 inserted. As shown in the figure, one end of the sample holder 4 reaches almost the center of the electron optical column 1, and the other end, that is, the connecting portion of the voltage cable 5 of the grip 11 is gripped from the electron optical column 1. It is arranged at a position protruding outward by the length of eleven. If the repeater 6 (strictly, the position of the connection terminal with the cable) is arranged on the gantry so as to be included in a circle with a radius L centering on the projection point on the gantry at the protruding position , The relationship of L> l is satisfied.

  Actually, since the voltage cable 5 needs to have a certain degree of slack, it is necessary to arrange the repeater 6 close to the electron optical column 1 to a considerable extent in order to satisfy the relationship of L> 1. is there.

  Next, details of the repeater 6 will be described with reference to FIGS. 3 and 4.

  FIG. 3A is an explanatory diagram illustrating a detailed example around the repeater according to the first embodiment. In particular, FIG. 3A shows a connection diagram between the internal wiring of the repeater 6 and the sample holder 4. A connector mounting detection switch 24 is provided in the repeater 6, while a power source 31 is provided in the high voltage source 7 disposed in the gantry 2. The power supply 31 is a power supply device for generating a high voltage. The high voltage source 7 is a high voltage supply device that generates a high voltage based on the supply from the power supply 31, and may be provided integrally with the power supply 31 or may be provided individually. .

  The conduction between the sample holder 4 and the high voltage source 7 is controlled by high voltage control means 32 as a high voltage control unit.

  The connector mounting detection switch 24 as a connector detection unit operates in conjunction with the power source 31 of the high voltage source 7, and when the connector mounting detection switch 24 operates (no mounting is detected), the high voltage control means 32 causes a high voltage. The connection between the power source 31 of the source 7 and the BNC connector, that is, the sample holder 4 is cut off.

  The high-pressure control means 32 is also linked to the vacuum monitoring means 33 for monitoring the vacuum state of the sample stage 3, and the sample holder 4 is inserted into the sample stage 3, and the degree of vacuum has not reached the threshold value. In this case, the high voltage control means 32 is configured to block the conduction between the high voltage source 7 and the sample holder 4. Thereby, the application of the retarding voltage in the state where the insertion path of the sample holder 4 or the inside of the electron optical column 3 is at an insufficient vacuum is prevented. Therefore, a discharge accident can be prevented.

  The connector attachment detection switch 24 may be linked to the high voltage control means 32.

  Even if the voltage cable 5 is connected to the repeater 6 first, since the sample holder 4 is not contained in the sample stage 3, the high voltage control means 32 is blocked by the vacuum monitoring means 33. . On the contrary, when removing the sample holder 4 from the sample stage 3, it is necessary to remove the sample holder 4 from the sample stage 3 after removing the voltage cable 5 from the repeater 6. As a result, in a state where a high voltage is applied to the sample holder 4, the operation of removing the sample holder 4 from the sample stage 3 cannot be performed.

  As described above, in the configuration shown in FIG. 3A, when the voltage cable 5 is not properly connected to the repeater 6, the retarding voltage is not applied to the cable connection terminal of the repeater 6. It is possible to prevent an electric shock accident due to a poor connection with.

  FIG. 3B is an explanatory diagram illustrating another detailed example of the vicinity of the repeater according to the first embodiment. FIG. 4 is a perspective view showing a wiring structure inside the repeater according to the detailed example shown in FIG. 3B.

  FIG. 3B and FIG. 4 show the configuration of a repeater that further improves safety by providing a high-pressure guard. First, the appearance of this configuration example will be described.

  FIG. 4 shows a perspective view of a repeater provided with a high-pressure guard. The BNC connector A 17 provided on the voltage cable 5 is connected to the BNC connector B (female side terminal) 22 of the repeater 6 through the hole of the high voltage guard 21. The tip of the knob 25 provided on the high-pressure guard 21 is a tip screw 26. By turning the knob 25, the tip screw 26 is fitted to the screw 27 on the relay 6 side, and the high-pressure guard 21 is connected to the relay 6. It can be fixed to.

  When the BNC connector A17 is inserted (connected) into the BNC connector B22, the switch plate 23 is pushed and the connector mounting detection switch 24 operates. Further, when the tip screw 26 is attached to the screw 27, the pin 28 provided on the high-voltage guard 21 is inserted into the hole above the screw 27, and the high-voltage guard attachment detection switch 29 serving as the second switch of the repeater 6. To work.

  FIG. 3B shows a connection diagram between the internal wiring of the repeater 6 and the sample holder 4. The high voltage guard wearing detection switch 29 is linked to the high voltage control means 32 for controlling the state of the high voltage source 7 and other high voltage using parts, and the high voltage guard wearing detection switch 29 operates (no wearing is detected). The high voltage control means 32 is configured to cut off the conduction between the high voltage source 7 and the BNC connector.

  In the case of the configuration shown in FIGS. 3B and 4, the connector attachment detection switch 24 and the high-voltage guard attachment detection switch 29 detect attachment, and the sample holder 4 is further inserted into the sample stage 3, and the vacuum is pulled to a certain level. It is necessary for the vacuum monitoring means 33 to detect this. At this time, the power supply 31 of the high voltage source 7 and the high voltage control means 32 are operated so that a desired high voltage is output from the high voltage source 7 and reaches the BNC connector A17 via the voltage cable 8 from there. A high voltage can be introduced into 4.

  Next, a case where an operation of removing the BNC connector A17 of the voltage cable 5 extending from the repeater 6 from the sample holder 4 in a state where a high voltage is applied will be described. Before removing the BNC connector A17, the high-pressure guard 21 provided on the repeater 6 must be removed. When the high voltage guard 21 is not attached, the high voltage control means 32 is shut off, so that the high voltage is turned off. Moreover, since the fixing method of the high voltage | pressure guard 21 is a screw type, removal requires time. For this reason, the potential charged in the sample holder 4 is also eliminated within the time for removing the screw. With the above state, when removing the BNC connector A17, the risk of contact with a high voltage can be reduced.

  As described above, in the configuration of FIG. 3A described above, the high voltage can be cut off by removing the connector A17 even when a high voltage is applied to the sample holder 4, but in this case, the charge charged on the sample holder 4 is transferred to the operator's hand. There is a possibility of electric discharge (electric shock). In contrast, in the configuration shown in FIG. 3B, the high voltage can be cut off by removing the high voltage guard 21 before removing the connector A17. Thereby, since the charge of the sample holder 4 can be removed, electric shock can be prevented. That is, the high voltage guard 21 is removed to cut off the high voltage, and then the charge of the sample holder 4 is removed by the time lag until the connector A17 is removed, thereby preventing electric shock.

  With the above configuration, it is possible to avoid contact with the high voltage portion during the mounting operation and the detaching operation of the sample holder 4 on the sample stage 3. Therefore, a safe system for applying a high voltage to the sample stage 15 can be provided even in a configuration like the sample holder 4 in which the operator directly touches.

  3A and 3B show an embodiment of the connection diagram of the repeater 6, but the connection destination of the connector attachment detection switch and the high voltage guard attachment detection switch may be the same part, and is not limited to this example. . In FIG. 4, the switch structure and components of the repeater 6 are shown. However, the switch is not limited to a mechanical switch, and may be formed using a magnetic sensor or an optical switch.

(Example 2)
In FIG. 5, the external appearance whole view of the electron microscope of a present Example is shown. The electron microscope of the present embodiment is an electron microscope provided with a cover 41 surrounding the electron optical column 1 and the gantry 2 in addition to the functions equivalent to the functions of the electron microscope described in the first embodiment.

  In the electron microscope, the primary electron beam may be shaken by ambient noise or air flow by air conditioning, and may appear as noise in the sample image. Also, drift (image flow) may occur in the sample image as the ambient temperature changes and the electron optical column or stage expands and contracts. These phenomena occur more remarkably when acquiring a high-magnification image. As shown in FIG. 5, since the change of noise, air conditioning, and temperature can be suppressed by providing the cover 41, these adverse effects can be eliminated. Therefore, when performing the retarding method, which often obtains a high-magnification image, it is preferable to install a cover.

  In the present embodiment, a first door 42 for taking out the sample holder 4 from the sample stage 3 and a first door for performing maintenance such as mechanical electron optical axis adjustment by accessing from the front of the electron optical column 1. A second door 43 is provided on the cover 41. The repeater 6 is installed in the cover 41, and is preferably installed on the mount 2 in the vicinity of the first door 42, and the connector is attached by opening the first door 42. Here, the voltage supply cable 5 extending from the sample holder 4 is connected to the BNC connector B22 of the repeater 6. Preferably, in order to improve workability such as connector attachment / detachment, the repeater 6 uses the attachment surface of the BNC connector B22 as the attachment surface of the first door 42 or the second door 43 (door) on the cover 41. It is good to arrange | position on the mount frame 2 so that it may become parallel with respect to the open surface at the time of opening. In the example shown in FIG. 5, the repeater 6 is arranged so that the mounting surface of the BNC connector B22 faces the second door 43, and is set near the first door 42. Connection and removal of the connector from the door 42 to the repeater 6 can be easily performed. In FIG. 5, the repeater 6 has a box shape, but the repeater 6 may be embedded in a wall surface provided in the cover 41 as in the example illustrated in FIG. 6. Further, the direction of the BNC connector B22 in FIG. 6A is the same as the direction of the BNC connector B22 shown in FIG. 5, but the BNC connector B22 is placed on the upper surface of the repeater 6 as shown in FIG. May be suitable.

(Example 3)
In this embodiment, a configuration example of the in-lens SEM will be described.

  In FIG. 7, the external appearance whole view of the electron microscope of a present Example is shown. The in-lens scanning electron microscope of the present embodiment is an electron microscope provided with a cover 41 surrounding the electron optical column 1 and the gantry 2 in addition to the functions equivalent to the functions of the electron microscope described in the first embodiment. .

  The cover 41 is accessed from the front of the electron optical column 1 by a first door 42 for taking out the sample holder 4 from the sample stage 3, and a first door for performing maintenance such as mechanical electron optical axis adjustment. A second door 43 is provided. Furthermore, a third door 44 is provided so that the operation screen 45 can be easily confirmed when maintenance is performed on the second door 43. The operation screen 45 is mounted and used on a table indicated by a dotted line in FIG. 7, but the orientation of the screen can be appropriately changed as shown. Therefore, if the third door 44 is opened, the operator can view the operation screen when accessing the SEM main body via the second door 43 as indicated by an arrow in FIG.

  The repeater 6 is installed on the gantry 2 near the first door 42, and a connector is attached.

  FIG. 8 shows the positional relationship between the sample holder and the objective lens in a state where the sample holder of this embodiment is inserted into the electron optical column 1. An objective lens having a pole piece is provided in the electron optical column 1. The pole piece includes an upper magnetic pole 51 and a lower magnetic pole 52. A sample stage 3 is provided on the side surface of the electron optical column 1, and a sample holder 4 loaded with the sample 13 is mounted between the upper magnetic pole 51 and the lower magnetic pole 52 of the objective lens. Thus, since the in-lens SEM can realize strong excitation in a short focal state, it is suitable for high-resolution observation of a sample. The high voltage generated by the high voltage source 7 in this state is supplied to the sample stage 15 via the voltage cable 5 by the voltage introduction line 18 inside the sample holder 4 and acts on the primary electron beam 19.

  As described above, the electron microscope described in the embodiments of FIGS. 5 to 7 can realize high-resolution observation with a low irradiation voltage by the retarding method safely and easily. In addition, stable high-magnification observation that is hardly affected by noise around the apparatus and air conditioning can be realized. Furthermore, by combining with the in-lens SEM as in the embodiment of FIG. 8, it is possible to realize ultra high resolution observation with a low irradiation voltage by the retarding method.

1 Electron optical column 2 Mounting base 3 Side entry type sample stage (sample stage)
4 Sample holder 5 Voltage cable (voltage supply cable)
6 Repeater 7 High voltage source 8 Voltage cable 11 Grip 12 O-ring 13 Sample 14 Guide pin 15 Sample stage 16 Shaft 17 Connector A (BNC connector A)
18 Voltage introduction line 19 Primary electron beam 21 High voltage guard 22 BNC connector B
23 Switch plate 24 Connector mounting detection switch 25 Knob 26 Tip screw (knob tip screw)
27 Screw 28 Pin 29 High voltage guard wearing detection switch 31 Power supply 32 High voltage control means (high voltage control means)
33 Vacuum monitoring means 41 Cover 42 First door 43 Second door 44 Third door 45 Operation screen 51 Upper magnetic pole 52 Lower magnetic pole

Claims (14)

An electron including an electron optical column that irradiates a sample with a primary electron beam, detects secondary charged particles obtained by the irradiation of the primary electron beam, and outputs it as an image signal, and a gantry that supports the electron optical column In the microscope,
A sample holder having a sample stage on which the sample is placed and having a function of applying a voltage to the sample stage;
A voltage source for supplying a voltage applied to the sample stage;
A voltage cable connected at one end to the sample holder;
Furthermore, the repeater to which the other end of the voltage cable is connected is installed on the gantry. The electron microscope according to claim 1,
The length of the said voltage cable is shorter than the length from the grip end surface of the said sample holder to the end surface of a sample stand, The electron microscope characterized by the above-mentioned. The electron microscope according to claim 1,
An electron microscope comprising a connection terminal for connection to the repeater at the other end of the voltage cable. The electron microscope according to claim 1,
An electron microscope characterized in that the repeater includes detection means for detecting connection of the cable. The electron microscope according to claim 1,
The electron microscope includes a first switch for turning on and off the conduction between the sample stage and the voltage source. The electron microscope according to claim 5,
An electron microscope, wherein the repeater includes a second switch for turning on and off activation of the voltage source. The electron microscope according to claim 5,
An electron microscope comprising a BNC terminal provided at an end of the repeater and the voltage cable on the repeater side. The electron microscope according to claim 7,
The second switch is provided at the base of the BNC terminal on the repeater side;
The first switch is provided in the vicinity of the BNC terminal on the repeater side;
The electron microscope further comprises a ring-shaped cap for fastening the repeater and the BNC terminal of the voltage cable so that the first switch and the second switch can be turned on. The electron microscope according to claim 1,
A polyhedral cover that covers the electron optical column and the frame;
An electron microscope comprising a door provided on a side surface of the cover. The electron microscope according to claim 9,
An electron microscope characterized in that a first door and a second door are provided on a side surface of the cover. The electron microscope according to claim 9,
An electron microscope characterized in that a connection surface with the voltage cable provided in the repeater is provided on a surface other than the back surface of the repeater with respect to the door. A scanning system comprising: an electron optical column that scans a sample with a primary electron beam, detects secondary charged particles obtained by the primary electron beam scan, and outputs the image as an image signal; and a gantry that supports the electron optical column In electron microscope,
A sample holder having a sample stage on which the sample is placed and having a function of applying a voltage to the sample stage;
A voltage source for supplying a voltage applied to the sample stage;
A voltage cable connected at one end to the sample holder;
Further, a scanning electron microscope characterized in that a repeater to which the other end of the voltage cable is connected is installed on the mount. The scanning electron microscope according to claim 12,
A scanning electron microscope characterized in that the sample holder is a side entry type stage that is inserted into a lens barrel from a side surface of the electron optical lens barrel via a vacuum feedthrough. The scanning electron microscope according to claim 12,
A scanning electron microscope characterized in that the electron optical column includes an in-lens objective lens.